Got curious, downloaded this stuff in the mean time and I think you shouldn't bother. All the files are *.txt files. Functions are *.mcfunction files. That should be a first warning to determine rubbish from something good.
Second: Python inside a function? Who is this guy kidding? Not me. He even included a .py file. Question: he did manage to remember that a Python file has the .py extension yet doesn't remember the .mcfunction? Second warning.
My comment/suggestion: don't feed the trolls and/or idiots. That's all this guy is in my opinion.
Ok, that may have been a bit too harsh.
Rename all the *.txt files info *.mcfunction. Then use: /function:circle/2, or /function:circle/10, and so on.
Also be sure to remove the /tellraw commands at the end because that syntax is all wrong, can prevent the function from loading. I got 8.txt to work but only after plenty of editing. A nice commendable effort on the part of the author but due to the way he shared this stuff I'd say it's not worth your time. WorldEdit is but one mod away.